For a long time, the northwest frontier has been a transit point for cultural exchanges between China and the West, and it has also been a battleground for military strategists to unify China since the Qin Dynasty. Because the environment in the Central Plains is suitable for living, there are plateaus and mountains in the southwest and vast seas in the east, the communication between the east and the west is not smooth, while the environment in the northwest is bad, but it is the only channel for communication between the east and the west. Historically, both Huns and Mongols on horseback thought northwest strategy was important. It can be said that it is a battleground for military strategists, which explains why the Han, Tang, Ming and Qing Dynasties spent huge military expenses to do their best in the whole country, but also expelled the opposing forces in the barren land of northwest China, established jurisdiction institutions and exerted their influence.
Every time the Central Plains region is updated, the northwest region under the power vacuum will fall into war again. In the history of the Western Han Dynasty, Emperor Wu painstakingly managed the Western Regions for decades. Then, with the chaos of Wang Mang, the world was in chaos, and the Central Plains dynasty lost control of the western regions. Then in the Eastern Han Dynasty, Ban Chao sent a mission to the Western Regions, regained control of the Western Regions and established a protectorate of the Western Regions. All the countries in the Western Regions obeyed the authority of the Central Plains Dynasty and maintained a stable order. However, after the weakness of the Eastern Han Dynasty, the Three Kingdoms fought the rebellion of the Eight Kings in the Western Jin Dynasty, and when the Central Plains was the weakest, the nomadic people in the northwest region coveted the Central Plains, established their own political power and entered the Central Plains, forming a confrontation with the Southern Han regime, and entered the era of "Five Rebellions in China".
Unlike the Central Plains Dynasty, most of the ethnic groups in the northwest are only Han Chinese. The geographical position of the northwest belongs to Central Asia to a great extent. This is the center where different ethnic groups meet and where ethnic conflicts break out. Macedonia, Persia, Arabia and Mongolia all want to control this place, and the survival of nomadic people is closely related to the environment. If they want to move, conflicts will inevitably break out. Therefore, the instability in the northwest region is also inevitable.